I wonder why we do things like that to ourselves? Last night I watched a video on signs that one has abandonment issues, and one of the top comments was "how many of us watched this just to affirm what we already know is true?" as though many of us were afraid we didn't really have abandonment wounds, but just wanted to feel that way to justify our issues or something.
Where do you you think those kinds of feelings of self-loathing come from?
What movie was it? Sounds interesting.
I think it may be due to our unconscious programming as well as the nature of our brain. When a child is young, it learns certain things through observation, listening and repetition. If it is taught that it is bad or worthless, or a parasite - or any other degrading notion - it won't start to fully believe it by it will start asking questions if it is true.
I have a theory on why it turns into such self-destructive behaviours actually. You see, a human brain is, more or less, a problem-solving machine. When a child (or an adult but especially a child due to its vulnerability) is degraded or even mistakenly told things (like a wrong type of a compliment), it stands before 2 problems.
Problem 1: Why does the parent/guardian/person say/do the things they do?
Problem 2: Maybe... They're right?
Since even while we're not aware of it the brain keeps solving problems, it uncousciously starts to come up with solutions to them - and because of its vulnerability, the child doesn't have an ability of adult reasoning and will most often trust the words of a guardian - as such it will try to find 'solution' to the Problem 1 by answering positively to Problem 2 and arranging situations to prove it.
Which is why it's so important to make sure our brains, powerful as they are, have proper problems to solve and that the problems they try to solve don't contradict themselves. For example, if someone with a very low self-esteem tries to diet and loose weight, they can have this kind of an unconscious thinking process:
Problem 1: I want to lose weight.
Problem 2: I'm sure that I can't do it. I'm not strong/good enough, too lazy etc. Besides, even losing weight won't make me look good.
The Problem 2 contradicts Problem 1 and causes our own behaviour to destroy the notion of losing weight and solidify view of not being able to.